A Macrocycle Based on a Heptagon‐Containing Hexa‐<i>peri</i>‐hexabenzocoronene
Vicente G. Jiménez, Arthur H. G. David, Juan M. Cuerva, Víctor Blanco, Araceli G. Campaña
Abstract
Abstract A cyclophane is reported incorporating two units of a heptagon‐containing extended polycyclic aromatic hydrocarbon (PAH) analogue of the hexa‐ peri ‐hexabenzocoronene (HBC) moiety (hept‐HBC). This cyclophane represents a new class of macrocyclic structures that incorporate for the first time seven‐membered rings within extended PAH frameworks. The saddle curvature of the hept‐HBC macrocycle units induced by the presence of the nonhexagonal ring along with the flexible alkyl linkers generate a cavity with shape complementarity and appropriate size to enable π interactions with fullerenes. Therefore, the cyclophane forms host–guest complexes with C 60 and C 70 with estimated binding constants of K a =420±2 m −1 and K a =(6.49±0.23)×10 3 m −1 , respectively. As a result, the macrocycle can selectively bind C 70 in the presence of an excess of a mixture of C 60 and C 70 .